<!DOCTYPE html>
<html>
	<head>
		<title></title>
		<style >
			div{
				width:100px;
				height:100px;
				border:1px solid #1E90FF;
				float:left;
			}
			#outer{
				width:204px;
				height:204px;
				margin:0 auto;
				float:none;
			}
		</style>
	</head>
	<body>
	 <div id="outer">
      <div>div1</div>	
	  <div>div2</div>	
	  <div>div3</div>	
	  <div>div4</div>	
	  </div>
	
	</body>
</html>